As is always the case, there will be extreme views on both sides of every moving issue. And it is only by seeing the extreme views does the culture find its equilibrium more towards the middle. So what will happen is the same thing that happens on every issue... the culture at large sees how things are travelling in the direction of "change" (with those with the most extreme "change" views out in front)... and somewhere down the line the people out front go over the tipping point and make most of the people behind them stop and say "Yeah, okay, that's a bit too far, even for us."
For all complaints about "slippery slopes"... they almost always end up being rather gentle slopes with a whole lot of bumps on the way. And society never goes careening forward like so many people in the far back want to believe it's going to. And then 20 years down the line we look back and think "This is really what got people so up in arms? Seriously?" And the supposedly "slippery slope" event looks positively quaint.
The "Satanic Panic" of the 80s? We now see it as rather silly and that "slippery slope" end up being practically flat. And did the removal of devils and demons from 2E end up actually affecting any of us in any meaningful way? Not even close. Yeah there was a lot of hue and cry about getting our assassins and devils taken out of our D&D... but after a few years the equilibrium was found and it became rather obvious that it hadn't been necessary. No book burning "slippery slope" ever occurred. And what about the harbingers of Satan in the late 80s... like the band 2 Live Crew and comedian Andrew Dice Clay? Two things that people out on the front of the extreme wave of censorship tried to get removed. How well did that work? Did that "slippery slope" end up removing all traces of sexually charged and casual misogyny in music and comedy heading into the 90s? Uh... nope. The worst we got is having "Parental Advisory - Explicit Lyrics" plastered on the front of all the CD cases. Ooh boy! What a hardship that was!
So what is going to happen in this case? Well, first of all... most of the people who are complaining about it will probably never even experience it because they either already own the OA book and weren't going to buy a copy of it off of DriveThru anyway... they will buy a copy of it NOW before anything happens just to "stick it" to whomever wants its removal... or the hue and cry will die down, the product may or may not get removed or have a disclaimer put on it, and then it won't be until 5 years from now someone will finally notice it happened and folks will go "Really? That happened? Oh, okay" and not give a rat's ass. Because why would we? It's a 30+ year old product for an edition that very few of us play, and which we never would even give a passing thought to until someone else brought it up.